Temperature controlling mechanism



P 3, 1942 R. E. D] V-ETTE 2,295,100

TEMPERATURE CONTROLLING MECHANISM Filed Jan. 27, 1941 .INVENTOR. gan l olpk ERUiV'ci-iv. BY 7 ATTORNEY ?ateoted e rte @QNTEQEHNG Randolph Yvette, Minneapolis, Mints, as sigoor to Minneapolis-Honeywell Regulator ilompasy, Mlpriecpo Eelewere its, Miran, a corporstlop of @lelms.

The present invention relates to tempergture controlling mechanism and particularly to rare-- torlzedvalves, and one of its objects is to provide an improved valve control means whereby the valve may be driven by on automatically con-- trolled motor to any one'ol three positions-tor example full open, intermediate and closed.

Another object of this invention is to construct a motor-driven valve which may be moved to either intermediate or full open position by the motor, and in which a greatly simplified and improved switching mechanism is provided. I

A further object of the present invention is to construct a two-stage motorls biased to closed position, and wherein two motor windings are provided, one to hold the valve is intermediate position, the other to hold the valve in full own position, and both windings act together to move the valve against its bias.

A further object of the invention is to provide an improved motorised regulator of the type which is biased to a first position and which is moved and held in either a, second or a third posltlcn depending on whether one or oath of two thermostatically operated sequentially actuated switches are closed.

Other objects oi the invention will be apparent from c consideration of the accompanying spec!- flcatlon, claims sud drawing, in which:

Figure l is a diagrammatic view of a control system embodying my invention, and

riven valve which Figure 2 is a detail, sketch showing certain I parts of the device cities.

In the drawing, 9% represents a gas burner which is supplied with fuel through a pipe H in which a valve 52 is located, The valve 52 is operated by means of a stem l3 projecting upwardly therefrom, the upper end of which is connected to a lever arm M. The left-hand end of the lever arm I4 is pivotally connected to a. vertical link E5. The upper end of the vertical link I5 is provided with a hook which cooperates with a. pin 2| attached to a gear 22. The "gear 22 is the last of a. train, generally indicated at 23, driven of Figure 1 iii a different poby a motor 24, which is provided with two stator windings 25 and 26'. v

The gear 22 is mounted on the same shaft with a pair of cams 30 and 3| which operate switch arms 32 and 33 against contacts 34 and 35, respectively.

The valve I2 is provided with a spring or other internal biasing means (not shown) which tends to keep it in closed position and is capable of moving the valve and gear train to closed posttion when the motor is rleeherglzed. The valve means may, desired, he hissed as shown in the patent to Shipley 2,222,93d.

The operation of the motor is controlled by s thermostat generally indicated at ll? which is located in the room or space being heated and consists of a bimetallic elem-est op rating arm :32. As indicated in the drawing, the operation of the bimetallic element is such to move the arm 32 to the right the temperature decreases. Pivotally sttached to the arm E2 is a, double ended contact err: of magnetic material. One end of the cor: which is longer than the other cooperates with a statiohmy contact 54 and the shorter end cooperates with a stationary contact Permanent mag nets 36 and ll ere provided odjacent each of the stationary contacts so as to give snap-action of the thermostat switches in a, manner .to be described later.

The system is supplied with energy through a. transformer 59 having a primary windhig 5i and 2 secondary winding 52.

Means are provided for holding the valve 92 partially open when the system is energized as a result of power failure. This means includes a rod 53 operated by or push button ii -l. The rod 53 is biased for movement to the left by a compression spring 58 surrounding the rod between the button 56 and a fixed part which supports the rod. During left-hand end of the lever i may be manually moved upward and the push button 5 5 may then be operated so that the end of the rod 53 prevents downward movement of the lever 84. An insulating disk 55 on the rod 53 engages a flexibly biased switch arm 55 and normally tends to hold it out of engagement with the stationary contact 57. When the disk 55 moves to the right, however, the bias of the switch arm 56 carries it into engagement with contact 51.

Operation When the parts are in the positions shown in Figure 1, the thermostat is satisfied and the valve is in closed position. Let it be assumed that the temperatureladjacent the thermostat 40 now decreases so that the switch arm 43 moves toward power failure conditions the tact 44. This completes an energizing circuit for both the windings 25 and 26 of motor 24. The energizing circuit for winding 25 may be traced from the right-hand end of transformer secondary 52 through a conductor 66,.a conductor 6i, contact 44, switch arm 43, thermostat 46, conductor 62, switch arm 32, conductors 63 and 64, contact 35, switch arm 33, conductors 65 and 66, winding 25 and aconductor 61 to the left-hand end of transformer secondary 52. The energizing circuit for winding 26 follows the circuit last described to the conductor 63 and passes from there directly through the winding 26 and conductor 61 to the left-hand end of transformer secondary 52.

As a result of the energization of these windings, the motor 24 drives the gear train 23 in such a direction that the pin 2| engages the hook 26 and lifts the lever |4 so as to open the valve. This action continues until the cams 36 and 3| reach the position shown in Figure 2. The switch arm 33 then drops into the notch 36 on the cam 3|, thus opening the circuit through the winding 25. The windings 2'5 and 26 are so proportioned that the torque produced by either one alone is not sufficient to operate the motor 24 so as to move the valve I2, but is suflicient to hold the valve '2 against its bias. When the energizing circuit for winding 25 opens, therefore, the motor remains in the position it has attained, holding the valve in an intermediate open position- If the temperature in the room or space being heated continues to decrease, the shorter end of the contact arm 43 is moved toward the stationary contact 45. As this movement takes place the lower end of the arm 43 moves into the field of magnet 41 and is attracted into an engagement with the contact 45 with a sudden snap action.

This completes a new energizing circuit for the winding 25. This circu't may be traced from the right-hand end of transformer secondary 52 through conductors 66 and 6|, contact 44, switch arm 43, contact 45, conductors 16 and 66, winding 25 and conductor 61 to the left-hand end of secondary 52. Since both motor windings are now energized, the motor again starts in operation to move the valve towards its full open position.

As soon as this motion starts the switch arm 33 rides out of the notch 36 on the cam 3| and again engages the contact 35. Simultaneously, the switch arm 32 drops to the low portion 31 of the cam 36 thereby separating from the contact 34. As the result of these changes, the previously described energizing circui for winding 26 is replaced by a new one which may be traced from the right-hand end of secondary 52 through conductors 66 and 6 I, contact 44, switch arm 43, contact 45, conductors 16 and 65, switch arm 33, contact 35, conductor 64, winding 26 and conductor 61 to the left-hand end of secondary 52.

Both windings continue to be energized in this manner until the valve reaches its full open position at which time switch arm 33 drops into a notch 36 on the cam 3|, thus opening the energizing circuit of the winding 26. The winding 25 remains energized and is effective to hold the valve in open position against its bias.

If the temperature in the space being heated now begins to rise, the lower end of the contact arm 43 separates from contact 65, thereby breaking the circuit through the winding 25. The valve |2 then moves toward closed position under the influence of its internal bias until the switch arm 32 rides out oi the low portion 31 of cam 39 and again engages the contact 33. This occurs when the valve has reached its intermediate position. When this contact is made the circuit first traced for the winding 26 is again completed and that winding becomes effective to hold the valve in its intermediate position.

If the temperature still continues to increase, the switch arm 43 will be moved out of engagement with the contact 44 and both windings oi the motor will be deenergized. The valve will then return to its closed position under the action of its internal biasing spring.

When the valve is manually operated to open position during power failure conditions, the rod 53 is so placed that the valve is held in a position between its normal intermediate and full open positions. As previously mentioned, the switch arm 56 is closed against the contact 51 at this time.

The closure of this switch completes energizing circuits forv both the motor windings. The circuit for winding 25 may be traced from the righthand end of secondary 52 through conductors 66.

and 1|, switch arm 56, contact 51, conductors 12, 65 and 66, winding 25 and conductor 61 to the left-hand end of secondary 52. The circuit for winding 26 maybe traced along the circuit last described to conductor 12, and thence through switch arm 33, contact 35, conductor 64, winding 26 and conductor 61 to the left-hand end of secondary 52.

As soon as power is returned to the system, current flows through these last two circuits and energ zes the motor. Since the pin 2| is not engazed by the hook 23 at this time, the motor is unloaded and therefore does not stop when the switch arm 33 drops into the notch 36 on cam 3|. The motor continues to run until the pin 2| engages the hook 26 and then lifts the left-hand end of lever l4 from the rod 53. The spring 58 thereupon moves the rod 53 to the left and the disk 55 engages the switch arm 56 and separates it from the contact 51. This will open the motor energizing circuits and the valve will drop back to its closed position. Of course, if the thermostat 46 is calling for heat at this time the motor 24 is energized through the circuits previously described to move the valve to the position indicated and hold it there.

It should be apparent to those skilled in the 'art that my invention may be used in other devices than that described herein. It should be understood, therefore, that I am to be limited only by the scope of the appended claims.

I claim as my invention:

1. In combination, a condition controlling device movable between first and second positions, means biasing said device to said first position, a rotary electrical motor operatively connected to said device and having a pair or windings of substantially equal strength, either of said windings, when energized, providing torque suflicient to v hold said device against the action of said-biasing means, and both of said windings, when energ zed, providing torque suflicient to move said device against said biasing means, main switching means including two pairs of contacts sequentially engageable, a first connection between I said switching means and said windings and etfective upon engagement of one of said pairs of contacts to energize both said windings, a second connection between said switching means and said windings and effective upon engagement of both of said pairs of contacts to energize both said windings, and further switching means positioned by said motor and effective when said windings.

said last-mentioned switching means.

. 3 said windings may be energized through one of said pairs of contacts.

being effective when said device is moved to said second position to interrupt said first connection completely and said second connection partially so as to deenergize the other of said windings.

2. In combination, a condition controlling device movable between first and second positions, means biasing said device to said first position, a rotary electrical motor operatively connectedto said device and having a pair of windings of substantially equal strength, either of said windings.

when energized, providing torque sutlicient to hold said device against the action of said biasing means, and both of said windings, when energized, providing torque sufiicient to move said device against ,said biasing means, main switch-= ing means including two pairs of contacts sequen= tially engageable, further switching means positionedby said motor, and connections between both said switching means and said windings,

both said switching means and said connections cooperating to energize said windings so as to move said device to said second position and hold it there when both of said pairs of contacts are engaged, and said switching means and said connections cooperating to energize said windings so as to move said device to a position intermediate said first and second positions and hold it there when only one of said pairs of contacts are engaged.

3. In combination, a valve biased to a first and inactive position, a motor operatively connected to said valve and having a pair of windings of substantially equal strength, either of said windings exerting suiiicient torque when energized to hold said valve against its bias, and both of said windings exerting sufiicient torquewhen energized to move said valve against its bias, a main control switch having two sequentially engageable pairs of contacts, further switching means positioned by said motor, and means including said further switching means operable when one of said pairs of contacts is engaged to energize both of said windings until said valve reaches a predetermined active position, whereupon one of said windings is deenergized, and operable when both of said pairs of contacts are engaged to energize both of said windings, until said valve reaches a predetermined second active position, whereupon one of said windings is deenergized.

4. In combination, a condition controlling device movable between inactive and active positions, means biasing said device to said first posi tion, a motor operatively connected to said device and having a pair of windings of substantially equal strength, either of said windings exerting sufficient torque when energized to hold said device against the action of said biasing means, and

both of said windings exerting sufficient torque when energized to move said device against the action of said biasing means, a main control switch having two sequentially engageable pairs of contacts, a first energizing circuit for one of said windings including one of said pairs of contacts, a second energizing circuit for the other of said windings including the other of said pairs of contacts, a first switch positioned by said motor and operable to interrupt said first circuit, and

- a second switch positioned by said motor and pings including one of said ,means including a erable, to connect said circuits so that both of of said biasing means, a main switching means including first and second pairs of contacts, a first energizing circuit for one Of said windings including said first pair of contacts, a second energizing circuit for the other of said windings including the second pair of contacts, a first switch in said first circuit between said first pair of contacts and said winding, a first cam driven by said motor and operatively associated with said first switch, an electrical connection joining a point in said first circuit switch and said winding with a point in said second circuit between said pair of contacts and said winding, a second switch in'said connec- "tion, and a second cam driven by said motor and operatively associated with said second switch, switch to open saidconnect on when said controlling device is in said second position and when said controlling device is in a position intermediate said first and second positions, and said first cam operating said first switch to open said first energizing circuit when said controlling .device is nearer said second position than said intermediate position. 6. In combination, a valve biased to a first position, a motor operatively connected to'said valve and having a pair of windings of substantially equal strength, either of said windings exerting sufiicient torque when energized to hold said valve against its bias, and-both of said windings exerting sufiicient torque when valve against its bias, a main control switch having two sequentially engageable pairs of contacts, a first energizing circuit for one of said windpairs of contacts, a second energizing circuit for the other of said windings including the other of said -pairs of contacts, and further switch means in said circuits positioned by said motor, said main switch and said further switch means cooperating when one of said pairs of contacts isengaged to energ'ize both of said windings until said .valve reaches a predetermined position, whereupon one of said windings is deenergized, and cooperating when both said pairs of contacts are engaged to energize both said windings until said valve reaches a second predetermined position, whereupon the other of said windings is deenergized.

7. In a control device for a fluid fuel burner, a valve controlling the flow of fuel to said burner, an electrical motor connected to said valve, said motor having a pair of windings of substantially equal strength, means biasing said valve to closed position and substantially equal in strength to one of said windings, and motor controlling device responsive to a condition indicative of the demand for burner operation, said motor control means being. operative upon said condition assuming a first predetermined value to energiz both said motor windings so as to open said valve by a first predetermined amount and then to deenergize one of said wind'-. ings, and operative upon said condition assumbetween said first energized to move said ing a second predetermined value to energize both said motor windings so as to open said valve by a second predetermined amount and then to deenergize the other of said windings.

8. in a control device for a fluid fuel burner, a valve controlling the flow of fuel to said burner, an electrical motor connected to said valve, said motor having a pair of windings of substantially equal strength, means biasing said valve to closed position and substantially equal in strength to one of said windings, means including both said windings to move said valve toward open position against the action of said biasing means, means includin one of said windings to hold said valve in open position against the action of said biasing means, and means including the other of said windings to hold said valve in a position intermediate said open and closed positions.

9. In combination, a condition controlling device movable between first and second positions through an intermediate position, means biasing said device to said first position, a rotary electrical motor operatively connected to said device for moving it away from said first position, said motor having a pair of windings each substantially equal in strength to said biasing means, means responsive to a condition indicative of the need for operation of said device including a member movable between first and second positions through an intermediate position in accordance with the magnitude of said indicative condition, motor control means including said condition responsive means and operative upon a change in position of said member away from said first position to energize both said windings, ,id motor control means also being operative w en both said member and said device are in ir intermediate positions to energize only one of said windings, and operative when both said member and said device are in their second positions to energize only the other of said windings, and operative at all other times to deenergize both said windings.

10. In combination, a condition controlling device movable between first and second positions through an intermediate position, means biasing said device to said first position, a rotary electrical motor operatively connected to said device for moving it away from said first position, said motor having a pair of windings each substantially equal in strength to said biasing means, means including both said windings to move said device toward said second position against said biasing means, means including one only of said windings to hold said device in said second position against said biasing means, and means including the other only of said windings to hold said device in said intermediate position against,

said biasing means.

RANDOLPH E, DI VE'I'I'E. 

